Method and apparatus for ablating cardiac tissue with guide facility

ABSTRACT

A method and apparatus for ablation of cardiac tissue at a selected cardiac location is achieved by providing at least one flexible elongated guide facility having a first end, a second end, and an intermediate portion extending between the first and second ends and by providing an ablation instrument which includes at least a pair of relatively moveable clamping jaws being disposed to engage and ablate the selected cardiac location. Each guide facility is adapted for introduction into a patient&#39;s chest through an opening and for advancement to the selected cardiac location such that the intermediate portion engages the selected cardiac location and the guide facility is withdrawn through the instrument receiving passage. At least one jaw of the ablation instrument engages with the guide facility and is guided to the selected cardiac location with the aid of the guide facility to ablate the selected cardiac location.

BACKGROUND OF THE INVENTION

[0001] This application is a non-provisional application which claimsthe benefit of provisional application Serial Nos. 60/464,713, filedApr. 23, 2003, and Ser. No. 60/547,364, filed Feb. 24, 2004, whichapplications are incorporated by reference herein.

[0002] Atrial fibrillation is the most common heart arrhythmia in theworld, affecting over 2.5 million people in the United States alone.Ablation of cardiac tissue, in order to create scar tissue that poses aninterruption in the path of the errant electrical impulses in the hearttissue, is a commonly performed procedure to treat cardiac arrhythmias.Such ablation may range from the ablation of a small area of hearttissue to a series of ablations forming a strategic placement ofincisions in both atria to stop the conduction and formation of errantimpulses.

[0003] Ablation has been achieved or suggested using a variety oftechniques, such as freezing via cryogenic probe, heating via RF energy,surgical cutting and other techniques. As used here, “ablation” meansthe removal or destruction of the function of a body part, such ascardiac tissue, regardless of the apparatus or process used to carry outthe ablation. Also, as used herein, “transmural” means through the wallor thickness, such as through the wall or thickness of a hollow organ orvessel.

[0004] Ablation of cardiac tissue may be carried out in an open surgicalprocedure, where the breastbone is divided and the surgeon has directaccess to the heart, or through a minimally invasive has direct accessto the heart, or through a minimally invasive route, such as between theribs, through a sub-xyphoid incision or via catheter that is introducedthrough a vein, and into the heart.

[0005] Prior to any ablation, the heart typically is electronicallymapped to locate the point or points of tissue which are causing thearrhythmia. With minimally invasive procedures such as via a catheter,the catheter is directed to the aberrant tissue, and an electrode orcryogenic probe is placed in contact with the endocardial tissue. RFenergy is delivered from the electrode to the tissue to heat and ablatethe tissue (or the tissue may be frozen by the cryogenic probe), thuseliminating the source of the arrhythmia.

[0006] Common problems encountered in this procedure are difficulty inprecisely locating the aberrant tissue, and complications related to theablation of the tissue. Locating the area of tissue causing thearrhythmia often involves several hours of electrically “mapping” theinner surface of the heart using a variety of mapping catheters, andonce the aberrant tissue is located, it is often difficult to positionthe catheter and the associated electrode or probe so that it is incontact with the desired tissue.

[0007] The application of either RF energy or ultra-low temperaturefreezing to the inside of the heart chamber also carries several risksand difficulties. It is very difficult to determine how much of thecatheter electrode or cryogenic probe surface is in contact with thetissue since catheter electrodes and probes are cylindrical and theheart tissue cannot be visualized clearly with existing fluoroscopictechnology. Further, because of the cylindrical shape, some of theexposed electrode or probe area will almost always be in contact withblood circulating in the heart, giving rise to a risk of clot formation.

[0008] Clot formation is almost always associated with RF energy orcryogenic delivery inside the heart because it is difficult to preventthe blood from being exposed to the electrode or probe surface. Some ofthe RF current flows through the blood between the electrode and theheart tissue and this blood is coagulated, or frozen when a cryogenicprobe is used, possibly resulting in clot formation. When RF energy isapplied, the temperature of the electrode is typically monitored so asto not exceed a preset level, but temperatures necessary to achievetissue ablation almost always result in blood coagulum forming on theelectrode.

[0009] Overheating or overcooling of tissue is also a majorcomplication, because the temperature monitoring only gives thetemperature of the electrode or probe, which is, respectively, beingcooled or warmed on the outside by blood flow. The actual temperature ofthe tissue being ablated by the electrode or probe is usuallyconsiderably higher or lower than the electrode or probe temperature,and this can result in overheating, or even charring, of the tissue inthe case of an RF electrode, or freezing of too much tissue by acryogenic probe. Overheated or charred tissue can act as a locus forthrombus and clot formation, and over freezing can destroy more tissuethan necessary.

[0010] It is also very difficult to achieve ablation of tissue deepwithin the heart wall. A recent study reported that to achieve a depthof ablation of 5 mm, it was necessary to ablate an area almost 8 mm widein the endocardium. See, “Mechanism, Localization, and Cure of AtrialArrhythmias Occurring After a New Intraoperative EndocardialRadiofrequency Ablation Procedure for Atrial Fibrillation,” Thomas, etal., J. Am. Coll. Cardioloqy, Vol. 35, No. 2, 2000. As the depth ofpenetration increases, the time, power, and temperature requirementsincrease, thus increasing the risk of thrombus formation.

[0011] In certain applications, it is desired to obtain a continuousline of ablated tissue in the endocardium. Using a discrete or pointelectrode or probe, the catheter must be “dragged” from point to pointto create a line, and frequently the line is not continuous.Multielectrode catheters have been developed which can be left in place,but continuity can still be difficult to achieve, and the lesionscreated can be quite wide.

[0012] Because of the risks of char and thrombus formation, RF energy,or any form of endocardial ablation, is rarely used on the left side ofthe heart, where a clot could cause a serious problem (e.g., stroke).Because of the physiology of the heart, it is also difficult to accesscertain areas of the left atrium via an endocardial, catheter-basedapproach.

[0013] Recently, epicardial ablation devices have been developed whichapply RF energy to the outer wall of the heart to ablate tissue. Thesedevices do not have the same risks concerning thrombus formation.However, it is still difficult to create long, continuous lesions, andit is difficult to achieve good depth of penetration without creating alarge area of ablated tissue.

[0014] As noted above, other forms of energy have been used in ablationprocedures, including ultrasound, cryogenic ablation, laser, andmicrowave technology. When used from an endocardial approach, thelimitations of all energy-based ablation technologies to date are thedifficulty in achieving continuous transmural lesions, and minimizingunnecessary damage to endocardial tissue. Ultrasonic and RF energyendocardial balloon technology has been developed to createcircumferential lesions around the individual pulmonary veins. See e.g.,U.S. Pat. No. 6,024,740 to Lesh et al. and U.S. Pat. Nos. 5,938,660 and5,814,028 to Swartz et al. However, this technology creates rather wide(greater than 5 mm) lesions which could lead to stenosis (narrowing) ofthe pulmonary veins. See, “Pulmonary Vein Stenosis after CatheterAblation of Atrial Fibrillation,” Robbins, et al., Circulation, Vol. 98,pages 1769-1775, 1998. The large lesion area can also act as a locuspoint for thrombus formation. Additionally, there is no feedback todetermine when full transmural ablation has been achieved. Cryogenicablation has been attempted both endocardially and epicardially (seee.g., U.S. Pat. Nos. 5,733,280 to Avitall, 5,147,355 to Friedman et al.,and 5,423,807 to Milder, and WO 98/17187, the latter disclosing anangled cryogenic probe, one arm of which is inserted into the interiorof the heart through an opening in the heart wall that is hemostaticallysealed around the arm by means of a suture or staples), but because ofthe time required to freeze tissue, and the delivery systems used, it isdifficult to create a continuous line, and uniform transmurality isdifficult to verify.

[0015] Published PCT applications WO 99/56644 and WO 99/56648 disclosean endocardial ablation catheter with a reference plate located on theepicardium to act as an indifferent electrode or backplate that ismaintained at the reference level of the generator. Current flows eitherbetween the electrodes located on the catheter, or between theelectrodes and the reference plate. It is important to note that thisreference plate is essentially a monopolar reference pad. Consequently,there is no energy delivered at the backplate/tissue interface intendedto ablate tissue. Instead, the energy is delivered at theelectrode/tissue interface within the endocardium, and travels throughthe heart tissue either to another endocardial electrode, or to thebackplate. Tissue ablation proceeds from the electrodes in contact withthe endocardium outward to the epicardium. Other references discloseepicardial multielectrode devices that deliver either monopolar orbipolar energy to the outside surface of the heart.

[0016] It is important to note that all endocardial ablation devicesthat attempt to ablate tissue through the full thickness of the cardiacwall have a risk associated with damaging structures within or on theouter surface of the cardiac wall. As an example, if a catheter isdelivering energy from the inside of the atrium to the outside, and acoronary artery, the esophagus, or other critical structure is incontact with the atrial wall, the structure can be damaged by thetransfer of energy from within the heart to the structure. The coronaryarteries, esophagus, aorta, pulmonary veins, and pulmonary artery areall structures that are in contact with the outer wall of the atrium,and could be damaged by energy transmitted through the atrial wall.

[0017] Several devices and methods utilizing ablation in the treatmentof atrial fibrillation have been described in co-pending applications tothe current inventor: Ser. No. 10/038,506, filed Nov. 9, 2001, which isa continuation-in-part of application Ser. No. 10/032,378, filed Oct.26, 2001, which is a continuation-in-part of application Ser. No.09/844,225 filed Apr. 27, 2001, which is a continuation-in-part ofapplication Ser. No. 09/747,609 Dec. 22, 2000, which claims the benefitof provisional application Ser. No. 60/200,072, filed Apr. 27, 2000.These applications are hereby incorporated by reference in the presentapplication.

[0018] Accordingly, it is the object of the present invention to providean improved method and apparatus for making transmural ablations toheart tissue.

[0019] It is a related object to provide a method and apparatus formaking transmural ablation in heart tissue that minimizes unnecessarydamage to the heart tissue.

[0020] It is a further object to provide a method and apparatus formaking transmural ablation in heart tissue that creates continuouslesions in a single step.

[0021] It is further an object to provide a method and apparatus forguiding the ablation instrument to a selected cardiac location prior toablation.

[0022] It is also an object to provide a method and apparatus forengaging cardiac tissue at a selected cardiac location.

[0023] It is still a further object to provide a method and apparatusfor ablating cardiac tissue which utilizes a sub-xyphoid approach.

SUMMARY OF THE INVENTION

[0024] These objects, and others will become apparent upon reference tothe following detailed description and attached drawings are achieved bythe use of an apparatus for ablating cardiac tissue. The apparatusincludes an elongated body having a distal end, a proximal end, andfirst and second jaws carried at the distal end. The first and secondjaws are moveable between a spaced apart open position and a closedposition. Each jaw comprises an ablating element connected to anablation source for ablating cardiac tissue between the jaws. Each jawfurther includes a channel which is distally located in relation to theablation element. A flexible elongated guide facility has first andsecond ends and an intermediate portion extending between the first andsecond ends. Upon positioning of the intermediate portion around aselected cardiac location, each end of the guide facility is slidablyreceived within a separate channel of the jaws so as to guide the jawsto the selected cardiac location for ablation thereof.

[0025] The method achieved by the use of the apparatus and includes thesteps of making a percutaneous incision to define an instrumentreceiving passage. The method is performed using the flexibly elongatedguide and an ablation instrument having at least a pair of relativelymoveable jaws, similar to that described above. The first end of theguide facility is introduced through the instrument receiving passage toa selected cardiac location adjacent one of the right and left pulmonaryveins. The guide facility is advanced to, preferably around, theselected cardiac location such that the intermediate portion of theguide facility engages the selected cardiac location. Then the first endof the guide facility is extended or withdraw to a position disposedoutside the instrument receiving passage such that first and second endsof the guide facility are positioned outside the instrument receivingpassage and the intermediate portion engages the selected cardiaclocation. Each of the jaws of the ablation instrument is cooperativelyengaged with a separate one of the ends of the guide facility. Theablation instrument is inserted through the instrument receiving passageand guided with the aid of the guide facility to the selected cardiaclocation such that the cardiac tissue at the selected location isdisposed between the jaws. The cardiac tissue at the selected locationis ablated.

[0026] The method and apparatus may be modified so as to be performedusing multiple guide facilities. Each guide facility including first andsecond ends and an intermediate portion extending between the respectiveends. By way of example and not limitation, a method and apparatus forusing two guide facilities is shown and described. A first end of afirst guide facility is inserted into the instrument receiving passage,which may be, and preferably is, accessed via a first sub-xyphoidincision. The first guide facility is advanced to a selected locationand then the first end is extended past the selected location to aposition outside of the patient through a second incision which providesaccess to the instrument receiving passage preferably through anintercostal or between-the-ribs incision. The intermediate portion ofthe first guide facility preferably engages one side of the selectedtissue to be ablated. A second guide facility is placed within thepatient's chest and follows the same instrument receiving passagebetween the two incisions except that the second guide facilitypreferably engages another side of the selected tissue. One end of eachguide facility preferably engages a separate jaw of the ablationinstrument so as to position the jaws on the sides of the tissue to beablated. A locating instrument and/or grasper may be used to facilitatevisualization or dissection of tissue around the selected locationand/or to provide tension to any of the guide facilities prior to orduring placement thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 shows an anterior plan view of the heart, the chest cavityand an access location for performing ablation.

[0028]FIG. 2 is a perspective view of the guide facility.

[0029]FIG. 3 is a perspective view of a second embodiment of the guidefacility.

[0030]FIG. 4 is a sectional view taken along line 4-4 of FIG. 2.

[0031]FIG. 5 is a sectional view taken along line 5-5 of FIG. 3.

[0032]FIG. 6 shows a sectional view of the guide facility in accordancewith the third aspect of the invention.

[0033]FIG. 7A-7D illustrate alternative embodiments of a first end ofthe guide facility.

[0034]FIG. 8 is a plan view of a locating instrument.

[0035]FIG. 9 is a end view of the locating instrument.

[0036]FIG. 10 is a sectional view of the locating instrument.

[0037]FIG. 11 is an enlarged sectional view of one end of the locatinginstrument with various instruments disposed within passageways.

[0038]FIG. 12 is an enlarged view of a distal end of an endoscope.

[0039]FIG. 13 is a plan view of a grasping instrument.

[0040]FIG. 14 is a cross-sectional side elevation view of a patient'schest illustrating the step of making a percutaneous incision to definean instrument receiving passage.

[0041]FIGS. 15-17 are cross-sectional side elevation views of thepatient's chest sequentially illustrating the step of introducing theguide facility through the instrument receiving passage and the step ofadvancing the guide facility to the selected cardiac location.

[0042]FIGS. 18-20 illustrate an enlarged posterior view of the leftatrium and left pulmonary veins illustrating the step of advancing theguide facility to the selected cardiac location such that theintermediate portion engages the selected cardiac location.

[0043]FIG. 21 is a cross-sectional side elevation view of a patient'schest illustrating the step of extending the first end of the guidefacility to a position disposed outside the instrument receivingpassage.

[0044]FIG. 22 is a cross-sectional side elevation view of a patient'schest illustrating the step of cooperatively engaging each of the jawsof a first embodiment of the ablation instrument with a separate one ofthe ends of the guide facility.

[0045]FIG. 23 is an enlarged sectional view of the distal ends of anablation instrument.

[0046]FIG. 24 is cross-sectional side-elevation view of a patient'schest illustrating the step of inserting the ablation instrument throughthe instrument receiving passage.

[0047]FIGS. 25-27 are enlarged posterior views of the left atrium andleft pulmonary veins sequentially illustrating the step of guiding theablation instrument with the aid of the guide facility to the selectedcardiac location and the step of ablating the cardiac tissue at theselected location.

[0048]FIG. 28 is a cross-sectional side elevation view of a patient'schest illustrating the step of ablating the cardiac tissue at a selectedlocation using a second embodiment of the ablation instrument.

[0049]FIG. 29 is a perspective view of the first embodiment of theablation instrument.

[0050]FIG. 30 is an enlarged plan view of the handle position of theablation instrument of FIG. 29, with portions removed to show detail.

[0051]FIGS. 31 and 32 are enlarged plan views of the jaw actuationmechanism for the ablation instrument of the FIG. 29.

[0052]FIG. 33 is an enlarged plan view of the jaws of the ablationinstrument of FIG. 29.

[0053]FIG. 34 is enlarged side view of the jaws of the ablationinstrument of FIG. 29.

[0054]FIG. 35 is a side view of the second embodiment of the ablationinstrument with portions shown in section.

[0055]FIG. 36 is an enlarged partial view of the inner edge of one ofthe jaw assemblies of the ablation instrument in FIG. 35.

[0056]FIG. 37 is an enlarged partial view of an inside of a jaw assemblyof a third embodiment of the ablating instrument.

[0057]FIG. 38 is a sectional view of the jaw assembly taken along line38-38 of FIG. 37.

[0058]FIG. 39 is an enlarged posterior view of the left atrium and leftpulmonary veins illustrating the step of ablating the selected cardiaclocation using the ablating instrument of FIG. 37.

[0059]FIG. 40 is a side view of the ablating instrument shown in FIG.37.

[0060]FIG. 41 is an enlarged posterior view of the left atrium and leftpulmonary vein illustrating the step of ablating the selected cardiaclocation using a fourth embodiment of the ablating instrument andincluding the guide facility.

[0061]FIG. 42 is a cross-sectional side view of a patient's chestillustrating another embodiment of the method and apparatus showingmultiple guide facilities, and showing the steps of introducing a guidefacility into the chest employing a sub-xyphoid approach and advancingthe guide facility to a posterior heart location, in particular showing,the vicinity of a pair of pulmonary veins.

[0062]FIG. 43 is a cross-sectional side view of a patient's chestshowing the step of extending the guide facility, as shown in FIG. 42,to a location outside of the patient's chest via an incision through theribs.

[0063]FIG. 44 is a cross-sectional side view of a patient's chestshowing another guide facility being inserted into the patient's chestvia a sub-xyphoid approach, engaging cardiac tissue and extended to alocation outside the patient via an intercostal incision, similar to theguide facility shown in FIGS. 42-43.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] The present invention provides a method and apparatus forablating cardiac tissue of the heart. Although the method for ablationwill be described by way of example but not limitation in relation tothe atrial tissue adjacent one of the right and left pulmonary veins,ablation of other areas of the heart are also possible.

[0065] As shown in FIG. 1 an incision 10 is made into the patient. Theincision in FIG. 1 is shown in the xyphoid region of the patient.Although the method of the present invention is performed via asub-xyphoid approach to ablate cardiac tissue, it is realized that otherapproaches may be utilized without departing from the scope of theclaimed invention such as, for example, intercostal and intravenous andother minimally invasive approaches as well as more invasive approachessuch as open chest procedures or approaches which remove all or aportion of the rib cage. FIG. 1 illustrates a patient's chest includinga rib cage R, sternum ST, xyphoid XP, coastal cartilage C, right lungRL, left lung LL and heart HT. The incision may be performed by one ofseveral medical instruments 11 such as a scalpel or the like. Once theincision is made, the opening defines an instrument receiving passage12, as shown in FIGS. 14-17, which allows for access to the heart HT forablation.

[0066]FIG. 2 illustrates a guide facility, generally at 14, forinsertion into the instrument receiving passage 12. The guide facility14 includes an elongated body 16, a first end 18, a second end 20 and anintermediate portion 22 which extends between the first end and thesecond end. The guide facility is generally made of a flexible materialto facilitate positioning of the guide facility into the patient forplacement around the cardiac tissue selected for ablation. Several typesof guide facilities are possible including but not limited to a wire, atube, surgical tape, or the like. For example, FIG. 3 illustrates asecond embodiment of the guide facility 15, with like parts shown withlike number, where the guide facility has an elongated tubular shape.Thus, it can be seen that the cross-sectional shape of the guidefacility may be circular, as shown in FIG. 4, such as where the guidefacility is a wire, or it may be tubular, as shown in FIG. 5, such aswhere the guide facility is a tube. A third embodiment of the guidefacility 17 is in the form of surgical tape, the guide facility may havea non-circular cross section such as that shown in FIG. 6. As shown inFIGS. 7A-7D, it is possible that one or both ends of the guide facility14 may have varying shapes for assisting introduction of the guidefacility through the instrument receiving passage 12 and placement ofthe guide facility at the selected cardiac location such as, by way ofexample, a conical or frustoconical end 18A, a spherical or circular end18B, a pyramidal end 18C, and a concave-sided end 18D.

[0067]FIGS. 15-18 illustrate the first end 18 of the guide facility 14being introduced through the instrument receiving passage 12 to theselected cardiac location. As shown in FIGS. 15-18, the selected cardiaclocation is shown at the left atrium LA adjacent the left pulmonaryveins LPV. FIG. 15 shows the guide facility being introduced through theinstrument receiving passage 12. In FIG. 16 the guide facility 14 isadvanced to the selected cardiac location at the left atruim LA. FIG. 17illustrates insertion of the first end 18 of the guide facility 14 intothe intrapericardial space after an incision has been made into thepericardium P.

[0068]FIGS. 8-13 illustrate a locating instrument, generally at 24,which may be, and preferably is, used in combination with the guidefacility 14 to locate the selection cardiac location and aid inintroducing and advancing the guide facility. In FIGS. 8-13 the locatinginstrument 24 includes an elongated body 26, a distal end 28, and aproximal end 30 and defines a plurality of passageways 32. The guidefacility 14 is inserted into one of the passageways 32 of the locatinginstrument 24 prior to introducing the guide facility into the patient.The combined locating instrument 24 and guide facility 14 is insertedinto the patient through the instrument receiving passage 12 andadvanced to the selected cardiac location, similar to the steps shown inFIGS. 15-18. The first end 18 of the guide facility 14 is adapted toextend beyond or forward of the distal end 28 of the locating instrument24 and this extension may be aided by a wire, spring mechanism,actuating linkage (not shown) and or other actuation methods apparent toone skilled in the art.

[0069] As shown in FIG. 11, the passageways 32 of the locatinginstrument 24 also may receive other instruments such as an endoscope,generally at 34, a grasper, generally at 36, as well as otherinstruments. The passageways of the locating instrument may be reducedto a 2-5 mm diameter or less for insertion of the instruments and guidefacility. Identifying and locating the cardiac tissue at the selectedcardiac location may be performed by the endoscope 34, a viewinginstrument or the like which is received within one or more of thepassageways 32. FIGS. 11-12 show the endoscope 34 which is insertablyreceived within one of the passageways 32 of the locating instrument 24,although it is also possible that the endoscope or other visualizationdevice may be embedded within the locating instrument or formedintegrally therewith. The endoscope 34 includes an elongated member 38having a distal end 40 and a proximal end 41. The distal end 40 of theendoscope 34 may be adapted to extend beyond the distal end 28 of thelocating instrument 24 and is preferably made of clear or transparentmaterial so as to allow viewing of cardiac tissue. In FIG. 12, thedistal end 40 of the endoscope includes visualization devices such as alens 42 and a light 44 for viewing the heart HT and is connected to aviewing device (not shown) located outside of the patient throughconnecting wires embedded within the elongated member 38 of theendoscope 34. Irrigation ports 46 may be defined within the distal end40 of the endoscope 34, which ports are fluidly connected to a fluidsource (not shown) at the proximal end 41, and an elongated tube 48supplies the fluid to the ports. As an alternative or in addition to thefluid supplied by the endoscope, one of the passageways 32 may beconfigured to allow for transmission of a fluid from the same orseparate fluid source which is fluidly connected to the passageway 32 atthe proximal end 30 of the locating instrument 24. Any type of fluid maybe used, preferably saline.

[0070] The endoscope 34 together with the locating instrument 24 mayassist in locating the cardiac tissue for ablation by dissecting cardiactissue. FIGS. 18-19 show the endoscope dissecting around the left atrialtissue adjacent the left pulmonary veins LPV. In FIG. 18, the endoscopedissects cardiac tissue at the left atrium LA adjacent the superior leftpulmonary vein LPV. The endoscope is advanced together with the locatinginstrument 24 and the guide facility 14 around the top or the superiorsurface of the left atrium towards the posterior surface of the heart.During dissection, the endoscope clears the operative field and createsa working and viewing space. If fluid is used, insufflation of the fluidaids in dissection of the cardiac tissue and facilitates in the creationof a working and viewing space adjacent the selection cardiac location.The first end 18 of the guide facility 14 is then advanced forward ofthe distal end 28 of the locating instrument 24. The locating instrument24 together with the endoscope 34 is withdrawn anteriorly while theguide facility remains positioned adjacent a posterior surface of theleft atrium LA adjacent the left pulmonary veins LPV. In FIG. 19, thelocating instrument 24 and the endoscope 34 is repositioned to dissectcardiac tissue at the left atrium LA adjacent the inferior leftpulmonary vein LPV. The guide facility may be disengaged or withdrawnfrom the passageway 32 of the locating instrument 24 prior or subsequentto repositioning of the locating instrument 24. Other dissectionapproaches are also possible. For example, dissection may be performedat the lower or inferior surfaces of the left atrium LA beforedissection of the upper or superior surface of the left atrium. Althoughit is preferred that the locating instrument 24 and/or endoscope 34 mayperform dissection first in one direction around the selected cardiaclocation and then in another direction which is generally opposite tothe first direction, other approaches may be used without departing fromthe scope of the invention.

[0071] Once the first end 18 of the guide facility 14 has been advancedto the selected cardiac location, such as the left atrium LA adjacentthe left pulmonary veins LPV in FIGS. 18-19, the first end 18 of theguide facility is advanced around the base of the left pulmonary veinsLPV to engage the selected cardiac location. As shown in FIGS. 19-20,this is performed preferably by pulling the first end 18 of the guidefacility around the selected cardiac location with the aid of thegrasper 36. The grasper 36 includes a body 50 and a distal graspingportion 52. The grasper 36 may be positioned in one of the passageways32 of the locating instrument 24 and adapted to extend from the distalend 28 of the locating instrument so as to engage the first end 18 ofthe guide facility 14. As shown in FIG. 19, the distal grasping portion52 engages the first end 18 of the guide facility, preferably in aclamping arrangement, and may be actuated by a linkage which is disposedwithin the locating instrument 24 and actuated at the proximal end 30thereof.

[0072] Once the distal grasping portion 52 engages the first end 18 ofthe guide facility, the grasper 36 together with the locating instrument24 may be withdrawn so as to pull the guide facility 14 around theselected cardiac location as shown in FIG. 20. In this way, theintermediate portion 22 of the guide facility 14 is disposed to engagethe selected cardiac location and in fact is positionedcircumferentially around the selected cardiac location. As shown in FIG.21, the locating instrument 24 together with the grasper 36 arewithdrawn through the instrument receiving passage 12. The distalgrasping portion 52 of the grasper 36 and the first end 18 of the guidefacility 14 remain in a clamping engagement so that when the locatinginstrument 24 and the grasper 36 are withdrawn through the instrumentreceiving passage 12, the first end of the guide facility is alsowithdrawn through the instrument receiving passage. So the guidefacility is disposed partially outside and partially inside the patientchest with the first and second ends 18, 20 of the guide facility 14positioned outside the instrument receiving passage 12 and theintermediate portion 22 of the guide facility engaging the selectedcardiac location within the chest of the patient.

[0073]FIGS. 22-27 illustrate positioning of an ablation instrument,generally designated at 54, and ablation of the selected cardiaclocation using the ablation instrument. The ablation instrument 54 is ofthe type shown in FIGS. 29-34 and includes first and second jaws 56 and58, respectively, and first and second handle members 60 and 62,respectively. Each jaw 56, 58 may be straight or curved. The jaws 56, 58define a working portion which may be between approximately 3-8centimeters in length. The two handle members 60, 62 define ring handleswhich are joined together for actuation of the ablation instrument 54.As best seen in FIG. 23, each jaw includes an ablating element 64, 66and each ablating element is connected to an ablation source 68,indicated in FIG. 24. In FIGS. 23, and 33-34, each of the first andsecond jaws 56, 58 include corresponding channels 70, 72, respectively,which are located at a jaw distal end 72, 76 of the first and secondjaws 56, 58. FIGS. 33, 34 illustrate that the first and second channels70, 72 form a bore throughout the thickness of the first and second jaws56, 58, although it is also contemplated that the first and secondchannels could be in the form of recesses along the exterior surface ofthe jaw distal end. Other shapes and orientations of the channels arecontemplated and will be apparent to those skilled in the art.

[0074] Turning to the ablation instrument 54 of FIGS. 29-34, the firstand second jaws 58, 56 are moveable between a spaced apart open positionand a closed position. The jaws 58, 56 of the ablation instrument 54 arebiased so that they are normally in a closed position, the jaws beingmoved to an open position by moving the two handle members 60 and 62towards each other. This action serves to withdraw a push rod 78, asillustrated in FIGS. 30-32, which is pivotally connected to the handlemembers 60, 62 by links 80, 82. With reference to FIGS. 31 and 32 thedistal end of push rod 78 includes two pins 84, 86 which are captured inslots 88, 90 in their respective jaw members 56, 58. When the pins 84,86 are located in the distal end of the slots 88, 90, the jaws are inthe closed position. The jaws 56, 58 open as the pins 84, 86 moveproximally in the slots 88, 90 through the withdrawal of the push rod 78by the closing of the handle members 60, 62.

[0075] The jaws 56, 58 also include a spring to bias the jaws toward theclosed position. With reference again to FIGS. 31 and 32, the jaws 56,58 are pivotally connected to each other by means of a pin 92. The pin92 is secured to the jaw member 58, but is received in an elongated-slot96 in the jaw member 56. The pin 92 is biased to the top of the slot 96,thus biasing the jaws 56, 58 to the closed position by means of leafspring 98 having one end secured by the pin 94 and the other endcaptured between two studs 100, 102 carried on the jaw member 56.

[0076] With reference to FIGS. 22-27, each of the first and second jaws56, 58 of the ablation instrument 54 is cooperatively engaged with aseparate one of the ends 18, 20 of the guide facility 14. Specificallyas shown in FIG. 23, the first end 18 of the guide facility 14 isslidably received within the first channel 70 of the first jaw 56 andthe second end 20 is slidably received within second channel 72 of thesecond jaw 58. Slidable engagement between the ends 18, 20 of the guidefacility 14 and the channels 70, 72 of the jaws 56, 58 is accomplishedby way of example when the first end 18 of the guide facility 14 isinserted into the channel 70 from an inner edge 104 of the jaw 56,although other engagements are possible without departing from the scopeof the invention. Insertion of the first end 18 of the guide facilitycontinues throughout the length of the channel 70 until the first end 18extends from an outer edge 106 of the first jaw 56. Similarly the secondend 20 of the guide facility 14 is inserted into the channel 72 at aninner edge of the second jaw 58 until it extends from the channel alongan outer edge of the jaw 58. This defines a cooperative engagementbetween each of the jaws 56, 58 of the ablation instrument 54 with aseparate one of the ends 18, 20 of the guide facility 14. Theintermediate portion 22 extends between the first and second ends 18, 20of the guide facility 14 between the jaws 56, 58 such that both the jaws56, 58 of the ablation instrument 54 and the guide facility 14 define anarea or a loop within which the selected cardiac location is disposedtherein. Tension can be provided at either or both of the first andsecond ends 18, 20 of the guide facility 14 to slidably advance theguide facility 14 through the channels 70, 72 to increase or decreasethe area defined by the loop. FIG. 22 illustrates that cooperativeengagement between each of the jaws 56, 58 of the ablation instrument 54with the first and second ends 18, 20 of the guide facility 14 isperformed outside of the instrument receiving passage 12 and prior toinsertion of the ablation instrument 54 through the instrument receivingchannel 12.

[0077] As shown in FIG. 24, once engagement between the jaws 56, 58 andthe ablation instrument 54 and the first and second ends 18, 20 of theguide facility 14 has been completed, the ablation instrument 54 isinserted through the instrument receiving passage 12. The ablationinstrument 54 proceeds along the path that which was previouslydissected by the locating instrument 24 and is guided to the selectedcardiac location with the aid of the guide facility 14. Tension can beprovided at either or both of the ends 18, 20 of the guide facility 14in the direction of the arrows to decrease the area defined by the loop.

[0078] As shown in FIGS. 24-27 the ablation instrument 54 is insertedinto the patient's chest and advanced to the left LA adjacent the leftpulmonary veins LPV. FIG. 24 illustrates when the ablation instrument 54is initially inserted into the instrument receiving passage 12. Duringinsertion of the ablation instrument 54, the first and second jaws 56,58 may be in a substantially closed position until the jaws are advancedto the selected cardiac location, where as illustrated in FIGS. 25 and26, the jaws 56, 58 are moved to an open position so as to receive theleft pulmonary veins between the jaws 56, 58.

[0079] With reference to FIGS. 25-26, the opened jaws 56, 58 areadvanced around the left atrium LA adjacent the left pulmonary veins LPVwith tension being provided at the ends 18, 20 of the guide facility 14until the jaw distal ends 74, 76 are located forwardly of the selectedcardiac location. Due to the slidable engagement between the guidefacility 14 and the jaws 56, 58, positioning of the ablation instrument54 at the left atrium LA is aided by the guide facility 14. The jawdistal ends 74, 76 are advanced towards the selected cardiac location sothat the ablating elements 64, 66 engage the cardiac tissue whichrequires ablation. FIGS. 26-27 show the jaws 56, 58 and the guidefacility 14, defining a substantially closed loop around the selectedleft atrial site such that the site is fully disposed between theablating elements 64, 66. Tension provided at the ends 18, 20 of theguide facility may assist in positioning the selected cardiac locationbetween the jaws 56, 58 as well as in capturing the cardiac location sothat it is in contact with the ablating elements 66, 68. Once thecardiac tissue is captured between the jaws as shown in FIG. 26, thehandle members 60, 62 are actuated to move the jaws 56, 58 towards eachother thereby clamping the selected cardiac location between the jaws,as best seen in FIG. 27. In this position, the ablation source 68 asshown in FIG. 24 may be activated so as to provide ablation energy tothe ablation elements 64, 66.

[0080] The ablation source 68 may be an energy generator, a lasersource, an electrical voltage, or a cryogenic fluid source, or any otherlike sources. Activation of the ablation source 68 allows ablation ofthe selected cardiac location so as to create an ablation line fortreating atrial fibrillation. Once the step of ablating has beencompleted, the jaws 56, 58 of the ablation instrument 54 are moved to anopen position so as to release the selected the cardiac location. Theablation instrument 54 is then withdrawn from within the instrumentreceiving passage 12 while the guide facility 14 is unthreaded from thechannel 70, 72 of the jaws 56, 58.

[0081]FIG. 28 illustrates ablation of the left atrium LA in accordancewith the claimed invention with a second embodiment of an ablationinstrument 112, which may similarly be utilized for both open chest andminimally invasive procedures in accordance with the present invention.

[0082] Turning to FIGS. 35 and 36, the ablation instrument 112 includesopposed parallel jaw assemblies 114, 116 with jaw assembly 114 beingfixed and jaw assembly 116 being movable between an open position asshown in FIG. 35 to a closed position, the spacing between the jawsbeing substantially uniform or constant. The jaw assemblies 114, 116 maybe curved or flat. The fixed jaw assembly 114 includes a fixed ablationelement 118 on the inside of the fixed jaw assembly 114 (the “inside”being defined as the side that contacts the tissue to be ablated).Correspondingly, the moveable jaw assembly 116 includes an ablationelement 120 which is located on the inside of the jaw assembly 116, asthis side is the side that contacts the tissue to be ablated and is inopposing relation to the ablation element 118.

[0083] Both ablation elements 118, 120 are likewise connected to anablation source, generally at 122, which is activated to ablate cardiactissue when the selected cardiac location is clamped between the jawassemblies 114, 116. The connection between the ablation elements 118,120 to the ablation source 122 may be effectuated by a wire or the likewhich extends through a drive shaft 124 of the ablation instrument 112.Clamping of the selected cardiac location between the jaw assemblies114, 116 occurs upon actuation of a moveable handle 126. The moveablehandle 126 is pivotally moveable in relation to a fixed handle 128 at ahandle end 130 so that when the moveable handle 126 is moved toward thefixed handle 128, the jaw assemblies 114, 116 are moved to a closedposition to clamp the selected cardiac location for ablation.

[0084]FIGS. 35-36 illustrate that each jaw assembly 114, 116 includeschannels 134, 136 disposed in jaw distal ends 138, 140 of the jawassemblies 114, 116 for slidably engaging the guide facility 14. Aspreviously described, a separate one of the ends 18, 20 of the guidefacility 14 is inserted into each channel 134, 136 prior to insertion ofthe ablation instrument through the instrument receiving passage 12.Accordingly, the ablation instrument 112 may be used to carry out thesteps of ablating cardiac tissue at the selected cardiac location withthe aid of the guide facility 14, similar to the ablation instrument inFIGS. 22-27. FIG. 28 shows cardiac tissue at the left atrium LA beingdisposed between the jaw assemblies 114, 116 for ablation.

[0085] In accordance with another aspect of the invention FIGS. 37-40illustrate a third embodiment of an ablation instrument, generally at152. By way of example, the ablation instrument 152 is shown of the typedescribed in FIGS. 35-36 although it also may be of the type describedin FIGS. 29-32 as well as any other type of ablation instrument. Theablation instrument 152 includes first and second jaw assemblies 154,156. Each jaw assembly 154, 156 includes a sensor 158, 160, which isdisposed in distal jaw ends or portions 162, 164, and an ablatingelement 166, 168.

[0086] As shown in FIGS. 38-39, the sensors 158, 160 are disposed on theinside of the jaw assemblies 154, 156, as this is the side whichcontacts the cardiac tissue for ablation. The sensors 158, 160 arepreferably disposed distally in relation to the ablating elements 166,168 and are adapted for sensing the presence of cardiac tissue betweenthe distal jaw ends 162, 164. Upon activation of the sensors 158, 160, aconductive pathway disposed between the sensors at the distal jaw ends162, 164 senses if cardiac tissue extends forwardly of the ablatingelements 166, 168 or, alternatively, the distal jaw ends 162, 164 so asto insure that the selected cardiac location is captured between the jawassemblies 154, 156 for ablation by the ablating elements 166, 168, asshown in FIG. 39.

[0087] In FIG. 40 actuation of the sensors 158, 160 is provided by anenergy source 170 which is connected to the ablation instrument 152 by awire 172 or other like conductive paths. prior to ablation. Prior toablation, the sensors 158, 160 are activated to determine whether or notan electrical impulse from cardiac tissue is occurring along aconductive pathway disposed between the sensors at the distal jaw ends162, 164. If the sensors 158, 160 detect the presence of cardiac tissue,the ablation instrument 152 may be repositioned until cardiac tissue isno longer detected between the distal ends 162, 164, as shown by way ofexample in FIG. 39, and then the ablation elements 166, 168 may beactivated to ablate the selected cardiac location.

[0088]FIG. 41 illustrates a further aspect of the present invention. Anablation instrument 174 has first and second jaw assemblies 176, 178.Each jaw assembly 176, 178 is moveable between an open position and aclosed position, and includes an ablating element 180, 182, a channel184, 186, and a sensor 188, 190. In accordance with a previouslydescribed aspect of the present invention, distal jaw portions 192, 194of the jaw assemblies 176, 178 may be cooperatively engaged with thefirst and second ends 18, 20 of the guide facility 14 prior to insertionof the ablation instrument through the instrument receiving passage 12.Accordingly, the ablation instrument 174 may be advanced to the selectedcardiac location at the left atrium LA with the aid of the guidefacility 14 until the selected cardiac location is disposed between thejaw assemblies 176, 178. Prior to ablation of the cardiac tissue at theselected location, the sensors 188, 190 may be activated to determinethe presence of cardiac tissue therebetween. If the sensors 188, 190 donot detect the presence of cardiac tissue then selected cardiac locationis ablated. Other variations in ablation instrument 174 are alsopossible. For example, although the sensors 188, 190 are shown asdistally located in relation to the channels 184, 186 on each distal jawportion 192, 194, it is also possible that the sensors 188, 190 could beposition proximally in relation to the channels 184, 186.

[0089]FIGS. 42-44 illustrates a modified method and apparatus forablating a selected cardiac location which employs multiple guidefacilities in a different orientation relative to the selected cardiaclocation than described above. In FIGS. 42-44 first and second guidefacilities 14A and 14B are similar to the previously described guidefacility 14, and like parts will be shown and described with the samenumbers following by corresponding letters A or B, as appropriate.

[0090] In FIG. 42, the first guide facility, generally indicated at 14A,is inserted into the incision which defines an opening 196 into thepatient's chest and instrument receiving passage. The guide facility 14Ais advanced to the selected cardiac location, such as for example theatrial tissue adjacent a pair of pulmonary veins. The locatinginstrument 24 may be, and preferably is, used to facilitate introductionof the first guide facility 14A. In FIG. 42, the locating instrument hasa handle member 200 at its proximal end and includes a control knob 202which is operatively connected to the distal end by a suitable actuatinglinkage so that movement of the control knob causes correspondingmovement of the distal end in a desired direction. As previouslydescribed, the locating instrument may be repositioned to dissectcardiac tissue and debris at the selected location above, below andaround the selected location and it further may utilize any of theinstruments previously described as being insertable into one of thepassageways 32 (FIGS. 10-11) of the locating instrument such as forexample, the endoscope 34 to permit visualization of the selectedlocation.

[0091]FIG. 42 shows the first end 18A of the guide facility 14A at alocation which is forward (“forward” being defined as the direction thatthe distal end of the instrument is pointing). The first guide facility14A is capable of being advanced beyond the distal end of the locatinginstrument and may be disengaged from the locating instrument, when itis desired to withdraw the locating instrument. The first end 18A of theguide facility is preferably advanced along one side of the selectedlocation in the vicinity of the selected cardiac location and, inparticular, is preferably placed adjacent the selected location whereone of the jaws of the ablation instrument will be placed. In FIG. 42,the first guide facility is advanced in a forward direction below thepair of pulmonary veins in the vicinity of the atrial tissue which isselected for ablation.

[0092] In FIG. 42 a second incision or opening 204 is made which ispreferably, but not exclusively, located between the ribs, and otherlocations are possible as previously discussed above. The secondincision 204 permits extension of the guide facility to a locationoutside of the patient. The grasper 36 may be inserted through thesecond incision and advanced to the selected location until its graspingportion 52 clamps the first end 18A of the first guide facility 14A tofacilitate extraction of the first guide facility. Introduction of thegrasper through the second opening to the selected location may be aidedby a suitable locating instrument which may be similar to the locatinginstrument 24 described above. It is possible to use the same locatinginstrument as that used to position the first guide facility, and ifused, the first guide facility 14A is preferably disengaged andpositioned adjacent the selected location prior to withdrawal andrepositioning of the locating instrument. Other instruments may also beused to aid introduction and positioning of the grasper and theseinstruments may be inserted through the second opening 204 or through aseparate incision such as that shown in FIG. 42 for the endoscope 34.

[0093] In FIG. 43, the grasper 36 is retracted or withdrawn through thesecond incision 204 and, in doing so, also draws the first end 18A ofthe guide facility through the incision 204. As shown in FIG. 43, thefirst end 18A extends to a position outside of the patient. Likewise,the second end 20A of the guide facility 14A extends to a positionoutside the opening defined by the first incision 196. Thus, the guidefacility extends throughout the entire instrument receiving passagedefined between the two incision openings 196, 204 with the intermediateportion 22A of the guide facility engaging the selected location.

[0094] The steps are preferably repeated for the second guide facility14B so that its first and second ends 18B, 20B extends outside therespective openings of the patient and the intermediate portion 22Bengages the selected cardiac location. As compared to the first guidefacility 14A, the second guide facility 14B is preferably, but notexclusively positioned at a different side of the selected location andeven more preferably at a location where it is desired to place theother jaw of the ablation instrument. In FIG. 44, the second guidefacility 14B is shown following a path above the pair of pulmonary veinsand in the vicinity of the atrial tissue. In this regard, the first andsecond guide facilities are disposed at different, and generallyopposite, sides of the pair of pulmonary vein to facilitate access tothe atrial tissue on opposite sides selected ablation site. Introductionof the second guide facility 14B also may employ one or both of thelocating instrument 24 and grasper 36. The locating instrument 24 may bedisengaged from the first guide facility 14A and withdrawn from theinstrument receiving passage to allow the second guide facility to beinserted into one of the passageways 32, or, alternatively, the locatinginstrument may be left within the instrument receiving passage and thesecond guide facility may be advanced to the selected location throughone of the passageways 32.

[0095] It is contemplated that the method may be utilized by employingthe first guide facility. In this regard, the method may be employedwithout the introduction of the second guide facility, if desired. Thefirst guide facility may be introduced, as previously described, intothe first opening of the instrument receiving passage and advanced tothe selected cardiac location. By way of example, and not limitation,the first guide facility may be advanced to posterior surface of theatrium below the pulmonary veins. The forward advancing end of the guidefacility is further advanced past the selected cardiac location and ispositioned outside of the second opening of the instrument receivingpassage. Then at least one jaw of the ablation instrument engages oneend of the first guide facility as the ablation instrument is guided tothe selected cardiac location.

[0096] The method of FIGS. 42-44 may employ any of the previouslydescribed ablation instruments such as those shown and described inFIGS. 29-34 or FIGS. 35-36 and any other modifications thereof. FIG. 44shows each jaw 206A, 206B of the ablation instrument engaging a separatesecond end 22A and 22B of the guide facilities. The channel defined ineach jaw receives a separate end which is inserted therein. Inaccordance with previously described embodiments each jaw may be inslidable engagement with the end of the respective guide facility andtension is provided to the inserted end of the respective guide facilityto advance the jaws in a forward direction toward the selected location.It is contemplated that other engagements are also possible. Forexample, one end or portion of the guide facility may be attached to thejaw, or another portion of the ablation instrument, by tying, clamping,hooking, looping or the like to provide tension to the attached ends ofthe guide facility and thus free the operators hands for other portionsof the procedure.

[0097]FIG. 44 shows the second ends 20A, 20B of each guide facilityattached to the respective jaw 206A, 206B to provide tension force.Tensioning force may also be applied to the first ends 18A and 18B toadvance the ablation instrument to the selected location. For example inFIG. 44, pulling the first ends 18A, 18B of the guide facilities may beused to advance the jaws of the ablation instrument around the pair ofpulmonary veins in the vicinity of the atrial tissue adjacent the veins.

[0098] Other variations in the method of the present invention are alsopossible. For example, the method may be performed on the epicardialsurface of the heart where the method includes the step of separatingthe pericardium from the selected cardiac location prior to ablation bythe ablation instrument. The jaws of the ablation instrument areinserted through an incision made in the pericardium P and advanced intothe pericardial space.

[0099] In addition, ablation of the selected cardiac location may beperformed by any of the ablation instruments described as well as otherablation instruments known to those skilled in the art. The presentinvention may be utilized to create a plurality of ablation lines atselected cardiac locations at different areas of the hearts for treatingatrial fibrillation. These ablation lines may be disposed to create anelectrical maze in the atria such as that utilized in the Mazeprocedure. Although the present invention is shown as ablating the leftatrium LA adjacent the left pulmonary veins LPV, is realized that themethod of ablation may be performed on other areas of the heart. Theseareas include but are not limited to the atrium adjacent the rightpulmonary veins, the left atrial appendage, the right atrial appendage,and other heart locations.

[0100] Another advantage of the ablation instrument is that it caneasily be adapted to a minimally invasive approaches such asintercostal, sub-xyphoid or other similar approaches. The ablationinstrument may been reduced to a 5 mm diameter device, and can probablybe reduced to 3 mm or less.

[0101] Accordingly, an apparatus and method for performing transmuralablation has been provided that meets all the objects of the presentinvention. While the invention has been described in terms of certainpreferred embodiments, there is no intent to limit the invention to thesame. Instead it is to be defined by the scope of the appended claims.

What is claimed:
 1. A method for ablating the pulmonary veins of apatient including: making at least one percutaneous incision to defineat least one opening of an instrument receiving passage; providing atleast one flexible elongated guide facility having a first end, a secondend and an intermediate portion extending between the first and secondends; providing an ablation instrument including at least a pair ofrelatively movable clamping jaws adapted to be connected to an ablationactivation source, the jaws being disposed to engage cardiac tissue at aselected cardiac location to ablate tissue therebetween; introducing thefirst end of the at least one guide facility through selected one of theat least one opening of the instrument receiving passage to a selectedcardiac location adjacent one of the right and left pulmonary veins;advancing the guide facility to the selected cardiac location such thatthe intermediate portion engages the selected cardiac location;extending the first end of the at least one guide facility throughselected one of the at least one opening of the instrument receivingpassage to a position disposed outside the instrument receiving passagesuch that the first and second ends are positioned outside of theinstrument receiving passage and the intermediate portion engages theselected cardiac location; engaging one jaw of the ablation instrumentwith one of the ends of the guide facility; inserting the ablationinstrument through the instrument receiving passage; guiding theablation instrument to the selected cardiac location with the aid of theguide facility such that the cardiac tissue at the selected location isdisposed between the jaws; and ablating the cardiac tissue at theselected location.
 2. The method of claim 1 wherein making at least onepercutaneous incision includes making a percutaneous incision.
 3. Themethod of claim 1 wherein making at least one percutaneous incisionincludes making first and second percutaneous incisions.
 4. The methodof claim 1 wherein advancing includes pulling the first end of the atleast one guide facility around the cardiac tissue at the selectedcardiac location such that the guide facility is circumferentiallypositioned in relation to the cardiac tissue.
 5. The method of claim 1wherein providing the at least one guide facility includes first andsecond guide facilities, each having corresponding first and second endsand an intermediate portion extending between the first and second ends,and wherein introducing, advancing and extending is performed for eachof the first and second guide facilities such that the intermediateportions engage different sides of the selected location.
 6. The methodof claim 1 wherein engaging at least one jaw includes positioning atleast one jaw of the ablation instrument in slidable engagement with oneof the ends of the at least one guide facility while the ablationinstrument is outside of the instrument receiving passage.
 7. The methodof claim 1 wherein engaging at least one jaw includes attaching at leastone of the jaws of the ablation instrument with one of the ends of theguide facility.
 8. The method of claim 1 wherein guiding the ablationinstrument includes providing tension to one or both ends of the guidefacility so that the ablation instrument advances to the selectedlocation.
 9. A method for ablating the pulmonary veins of a patientincluding: making first and second percutaneous incisions to definefirst and second openings of an instrument receiving passage; providingat least one flexible elongated guide facility having a first end, asecond end and an intermediate portion extending between the first andsecond ends; providing an ablation instrument including at least a pairof relatively movable clamping jaws adapted to be connected to anablation activation source, the jaws being disposed to engage cardiactissue at a selected cardiac location to ablate tissue therebetween;introducing the first end of the guide facility through the firstopening of the instrument receiving passage to a selected cardiaclocation adjacent one of the right and left pulmonary veins; advancingthe guide facility to the selected cardiac location such that theintermediate portion engages the selected cardiac location; extendingthe first end of the guide facility through the second opening to aposition disposed outside the instrument receiving passage such that thefirst and second ends are positioned outside of the instrument receivingpassage and the intermediate portion engages the selected cardiaclocation; engaging one jaw of the ablation instrument with one of theends of the guide facility; inserting the ablation instrument throughthe instrument receiving passage; guiding the ablation instrument to theselected cardiac location with the aid of the guide facility such thatthe cardiac tissue at the selected location is disposed between thejaws; and ablating the cardiac tissue at the selected location.
 10. Themethod of claim 9 wherein providing the guide facility includes firstand second guide facilities, each having corresponding first and secondends and an intermediate portion extending between the first and secondends, and wherein introducing, advancing and extending being performedfor each of the first and second guide facilities such that theintermediate portions engage different sides of the selected location.11. The method of claim 9 wherein engaging includes slidably receivingone of the ends of each first and second guide facility within anaperture which is defined at a distal end of each jaw of the ablationinstrument, wherein each jaw is slidably engaged with a different guidefacility.
 12. A method for ablating the pulmonary veins of a patientincluding: making a percutaneous incision to define an instrumentreceiving passage; providing a flexible elongated guide facility havinga first end, a second end and an intermediate portion extending betweenthe first and second ends; providing an ablation instrument including atleast a pair of relatively movable clamping jaws adapted to be connectedto an ablation activation source, the jaws being disposed to engagecardiac tissue at a selected cardiac location to ablate tissuetherebetween; introducing the first end of the guide facility throughthe instrument receiving passage to a selected cardiac location adjacentone of the right and left pulmonary veins; advancing the guide facilityto the selected cardiac location such that the intermediate portionengages the selected cardiac location; extending the first end of theguide facility to a position disposed outside the instrument receivingpassage such that the first and second ends are positioned outside ofthe instrument receiving passage and the intermediate portion engagesthe selected cardiac location; cooperatively engaging each of the jawsof the ablation instrument with a separate one of the ends of the guidefacility; inserting the ablation instrument through the instrumentreceiving passage; guiding the ablation instrument to the selectedcardiac location with the aid of the guide facility such that thecardiac tissue at the selected location is disposed between the jaws;and ablating the cardiac tissue at the selected location.
 13. The methodof claim 12 wherein the step of advancing includes pulling the first endof the guide facility around the cardiac tissue at the selected cardiaclocation such that the guide facility is circumferentially positioned inrelation to the cardiac tissue.
 14. An apparatus for ablating cardiactissue of a patient comprising: an elongated body including a distal endand a proximal end; first and second jaws carried at the distal end andmovable between a spaced-apart open position and a closed position, eachjaw comprising an ablating element connected to an ablation activationsource for ablating cardiac tissue located between the jaws; and firstand second flexible elongated guide facilities each including first andsecond ends and an intermediate portion extending between the first andsecond ends, upon positioning of intermediate portions at differentsides of a selected cardiac location of the patient one end of eachguide facility is engaged with a separate jaw so as to guide the jaws tothe selected cardiac location for ablation thereof.
 15. The apparatus ofclaim 14 wherein each jaw defines a channel which is distally located inrelation to the ablating element, each end of the guide facility isslidably received within a separate channel of the jaws.
 16. Anapparatus for ablating cardiac tissue of a patient comprising: anelongated body including a distal end and a proximal end; first andsecond jaws carried at the distal end and movable between a spaced-apartopen position and a closed position, each jaw comprising an ablatingelement connected to an ablation activation source for ablating cardiactissue located between the jaws, each jaw defining a channel which isdistally located in relation to the ablating element; and a flexibleelongated guide facility having first and second ends and anintermediate portion extending between the first and second ends, uponpositioning of the intermediate portion around a selected cardiaclocation of the patient each end of the guide facility is slidablyreceived within a separate channel of the jaws so as to guide the jawsto the selected cardiac location for ablation thereof.
 17. The apparatusof claim 16 wherein the jaws and the guide facility define asubstantially closed loop around the selected cardiac location, tensionbeing provided at one or both of the first and second ends of the guidefacility to decrease the area defined by the loop and capture theselected cardiac location between the jaws.
 18. An apparatus forablating cardiac tissue of a patient comprising: an elongated bodyincluding a distal end and a proximal end; first and second jaws carriedat the distal end and movable between a spaced-apart open position and aclosed position, each jaw comprising an ablating element connected to anablation activation source for ablating cardiac tissue located betweenthe jaws; and at least one flexible elongated guide facility havingfirst and second ends and an intermediate portion extending between thefirst and second ends, upon positioning of the intermediate portion atleast one side of a selected cardiac location of the patient at leastone end of the at least one guide facility is engaged with a at leastone jaw so as to guide the jaws to the selected cardiac location forablation thereof.
 19. The apparatus of claim 18 wherein each jaw definesa channel which is distally located in relation to the ablating element,and one end of the at least one guide facility is engaged within aseparate channel of the jaws.
 20. The apparatus of claim 18 wherein eachjaw defines a channel which is distally located in relation to theablating element, each end of the guide facility is slidably receivedwithin a separate channel of the jaws.